console.log("这是第三个")
let a = 10;
document.body.addEventListener('click',()=> {
    console.log("你好")
})
// document
var box = document.getElementById("box");
box?.addEventListener("click",()=> {
    console.log("帽子")
})
function fn1(a:string) {
    
    return console.log(a)
    // return console.log(this,a)
}
fn1("哈哈哈")
fn1("你好")
// fn1(33)